MEN OF MATHEMATICS
Finally, the curvature which-Riemann defined, the processes
which he devised for the investigation of quadratic differential'
forms (those giving the formula for the square of the distance
"between neighbouring points in a space of any number of:
dimensions), and his recognition of the fact that the curvature/
is an invariant (in the technical sense explained in, previous/'
chapters), al found their physical interpretations in. the theory
of relativity. Whether the latter is in its final form or not' is
beside the point; since relativity our outlook on. physical science
is not what it was before. Without the work of Riemaan this
revolution in scientific thought would have been impossible-;
unless some later man had created the concepts and the mathe-
matical methods that Riemann created.